40 Testing Milk and Its Products. 



slightly broken, or at any rate, are soon corroded so 

 that the numbers can only be seen with difficulty. 



The best and most permanent label for test bottles is 

 made by scratching a number with a marking diamond 



on the glass di- 

 rectly above the 

 scale on the neck 

 of the bottles or 

 by grinding a 

 number on the 

 bottle itself. In 

 ordering an " out- 

 fit, or test bottles 

 alone, the oper- 

 ator may specify 



FIG. 12. Waste-acid jar. that the bottles 



are to be marked 1 to 24, or as many as are bought, 

 and the dealer will then put the numbers on with a 

 marking diamond. 



A careful record should be kept of the number of the 

 bottle into which each particular sample of milk is 

 measured. Mistakes are often made when the operator 

 trusts to his memory for locating the different bottles 

 tested at the same time. 



46. Cleaning test bottles. The fat in the neck of 

 the test bottles must be liquid when these are cleaned. 

 In emptying the acid the bottle should be shaken in 

 order to remove the white residue of sulfate of limr, 

 etc., from the bottom; if the acid is allowed to drain 

 out of the bottle without shaking it, this residue will 

 be found to stick very tenaciously to the bottom of the 

 bottle in the subsequent cleaning with water. 



